The present invention relates to a surgical draping system for retaining sterile and clean conditions at an operation site. Surgical drapes are well known in the medical community and serve to prevent contamination of the sterilized operation site by foreign bodies, in particular micro-organisms. Two important potential sources of infection of the patient are the transfer of bacteria originating from unsterilized areas of his own body to the exposed tissue at the operation site and the airborne transfer of bacteria from other sources to the operation site such as lint or skin particles originating from the surgeon or other staff in the operating theater.
In the prior art, a wide variety of draping systems have been employed to improve sterility at the site of an operation. It is helpful to consider the features of these diverse systems to gain an appreciation of the object and subject of the present invention.
There are two main classes of surgical drapes: reusable drapes and disposable drapes. Before considering the action of drapes, it should at first be appreciated that micro-organisms can only be transmitted in a medium. They do not move freely on their own, i.e. they are transferred by fluids, aerosol droplets, lint, dust particles, skin particles or the like.
Historically cotton drapes were and still are used, as they are absorbent and soak up liquids. However, they provide no bacterial barrier. Even when replaced by polyester cotton drapes treated with liquid repellent finish, the properties are limited and are lost after a few uses. Both cotton and polyester cotton drapes are lint producers from the beginning and this production increases with each use. Latter-day fabrics for reusable drapes, such as ROTECNO (registered trade mark), which similarly present a sterile barrier to prevent infection have improved properties in a number of respects. For instance the fabric is liquid repellent, thereby still functioning as a sterile barrier when contacted by liquids, non-particle generating, and provided with a grid of crossed conductive fibers to prevent the build-up of static electricity, which when present can attract airborne particles and on discharge damage sensitive electrical equipment.
In use, such drapes are arranged around the operation site and held in position with clips which grip through the fabric onto the flesh of the patient. A single drape may be used, in which case there is an aperture in the drape which is appropriately dimensioned to allow access to the operation site. If a plurality of drapes are used, these may have a simple rectangular shape and are laid over the patient and overlap each other to form, for instance, a rectangular access area around the operation site. However, with such draping systems it is difficult to efficiently seal off the operation site from the surrounding non-sterile regions of the patient, as openings remain between the patient's skin and the drape through which micro-organisms can be freely carried. One particularly undesirable mode of patient self-infection is when fluids spilled during the operation flow under or through the drape to non-sterile regions of the patient, become contaminated and then return to the operation site, for instance by capillary action or under the application of pressure.
These fabric drapes do possess the key advantage that they are reusable, the fabric construction being suitable for typical hospital cleansing methods such as laundering followed by steam sterilization. However, over a period of time, the clipped regions of the fabric become damaged, thereby leading to further degradation of the operational conditions.
To avoid some of the shortcomings of clipping drapes, adhesive tapes can be applied to the edges of the drapes to adhere them to the patient's skin.
After laundering the reusable drapes, double-sided adhesive tape, which has a backing paper, for instance siliconized paper, is attached to the edge of the drape. The reusable drape together with the tape now one-sidely adhered to it, is then sterilized, usually steam sterilized at, for instance, 134.degree. C. Prior to the operation, the backing paper is pulled off the adhesive tape and the drape is adhered to the patient's skin at the site of the operation.
The problem then exists of thoroughly removing the adhesive tape from the drape. Experience has shown that it is tiresome to perform this manually, and therefore correspondingly difficult to supervise that overworked staff carry out this task adequately. In any case, residual traces of adhesive remain on the drape which must be fully removed by the cleansing or laundering procedure. This presents a particular complication for the adhesive, since it must satisfy conflicting requirements. Namely, on the one hand it must be able to withstand sterilization, in particular steam sterilization at 140.degree. C., without losing its adhesive properties, and on the other hand it should be fully removable in the cleansing process, in particular in normal hospital laundering.
Certain acrylate adhesive tapes go some way to fulfilling this task. However, during cleansing, the dissolvable glue bleaches out the color from the textile reusable drape. This results in a reusable drape which is still completely serviceable giving the appearance of being old and worn, which, in turn, frequently leads to staff disposing of the drape prematurely. Substantial unnecessary costs are thereby incurred. Also, the use of such adhesive tape represents a very substantial cost factor. It has been found in practice that the operating theater actually spends substantially more money on tape provided with this special adhesive than on the reusable drapes to which it is adhered.
As an alternative method, disposable drapes are also used; they are typically comprised of a non-woven cellulosic material. In some versions, the central part of the disposable drape is adhered to the operation site, and such drapes can be provided with an absorbent upper surface which is reinforced with plastic under the absorbent layer to act as a bacterial barrier.
Although the best of these drapes may provide an acceptable bacterial barrier, drapes of this kind are not intended to be cleaned or reused. Given the high throughput achieved in a modern operating theater, the use of such disposable drapes leads to the creation of large amounts of waste material requiring incineration with the ensuing undesirable costs and environmental consequences.
Therefore, it can be seen that a large number of approaches have been used in prior art draping arrangements and systems, each individual approach offering certain advantages but always associated with certain other disadvantages.
One general problem for all draping systems is that the number and variety of special drape designs required to meet all types of operations results in considerable costs, large storage space utilization and great administrative effort required to efficiently maintain adequate stocks of these items ready for operations.